Re: QUESTION - is it possible to get a TX output of CW in A1A?
Why not use a keyed audio oscillator with suitable level adjustment at the mic input?
On Wed, Apr 14, 2021 at 12:14 PM Evan Hand < elhandjr@...> wrote: Loris,
I do not claim to be an expert on mixers.? I am only an amateur at understanding how they work.? Here is what I think would happen.
The DC voltage would be a 0Hz signal that is being added to the BFO frequency which would put the BFO signal on the input to the SSB filter.? So yes to your question.? Biasing the product detector would pass the BFO signal to the SSB filter.? In the ?BITX v6 That would send an 11.056Hz signal to a filter that is designed to pass signals from 11.057MHz to 11.059MHz so there would be a much-reduced signal being sent to the following stages for frequency mixing and amplification.? In a properly adjusted rig that could be as much as 30db to 40db down.
Note that the above BFO and Filter frequencies are approximate for description only.? They would vary depending on the specifics set for the rig under test and the actual SSB filter characteristics.
If the intent is to use it for CW like is done in the first mixer of the ?BITX, then as is done there you would need to adjust the BFO frequency on key down so that it will generate the correct signal to get through the SSB filter, then further adjust one of the later mixers to be on the correct frequency to transmit.
Again, these are my thoughts.? I am open to any comments or corrections.
73
Evan
AC9TU
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Squaring off all the wires like that was typical of radios built 100 years ago:
? ??
? ??
Ten years later stuff got boxed up in a metal chassis to where people never saw the wiring,
and so it didn't need to be quite so pretty.? I go for that more modern look.
Jerry, KE7ER
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On Wed, Apr 14, 2021 at 08:13 AM, Jack, W8TEE wrote:
I know what you mean. Most of my kits look like controlled chaos even though you'd think a kit's PCB would make things look pretty good. Then there's the work by Dave Richards, AA7EE, where his Manhattan Style projects are works of art:
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Farhan:
I know what you mean. Most of my kits look like controlled chaos even though you'd think a kit's PCB would make things look pretty good. Then there's the work by Dave Richards, AA7EE, where his Manhattan Style projects are works of art:
Visit his web site and you'll find that all his stuff looks like this. Kinda makes me want to pack it all in and take up knitting.
Jack, W8TEE
On Wednesday, April 14, 2021, 10:59:02 AM EDT, Ashhar Farhan <farhanbox@...> wrote:
It is the economy of scale that kicks in with hf signals. It works out to be cheaper than the bill of materials! The way to keep the price under $100 is to build it the ugly way.? You can always scavenge from your junk. I can build an ugly radio in a day, in a pcb, it takes me a week! - f
On Wed 14 Apr, 2021, 4:56 PM Dennis Zabawa, < kg4rul@...> wrote: It seems their BOM totals $190USD.? You can buy a basic kit w/ acrylic front/rear panels and mike, shipped via DHL, for $160USD.? I guess there is a price for education!
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Jack, W8TEE
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Shirley is right, Vishay bought IR.
My story about the WA2EBY amp not working well at first with some non-IR IRF510 is vaguely mis-remembered.
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On Wed, Apr 14, 2021 at 03:10 AM, Shirley Dulcey KE1L wrote:
Vishay bought International Rectifier. The Vishay parts are the direct lineal descendents of the original IRF parts.
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It is the economy of scale that kicks in with hf signals. It works out to be cheaper than the bill of materials! The way to keep the price under $100 is to build it the ugly way.? You can always scavenge from your junk. I can build an ugly radio in a day, in a pcb, it takes me a week! - f
On Wed 14 Apr, 2021, 4:56 PM Dennis Zabawa, < kg4rul@...> wrote: It seems their BOM totals $190USD.? You can buy a basic kit w/ acrylic front/rear panels and mike, shipped via DHL, for $160USD.? I guess there is a price for education!
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
JG I am well aware of all that in fact the Gate capacitance of the IRFz24 is about double that of the IRF 510 BUT? in general these will be going in a bolt on amp that has about 4-5 Wats pushed up the Wazoo. so you and afford a? bit of loss to gate capacitance at least up to and including 15 Mhz.??
In situations where you want real control over Cin and reproducible characteristics you go for the 6 dollar a piece Mitsubshi? RF qualified Mosfets . Basically on cost there are not many other options. At that price you get source = Ground tab and a device that runs much much cooler as a result .
Where the Z24 shines is? 1. It is not often counterfeited.? and 2. Thermally it is a lot better if you look at? the data sheets. So if you have a pair of each in the same amp both running 30W out with marginal heat sinking then the IRF510s will expire a lot earlier as? they might be running 25 C hotter than the IRFz24s for the same Po.
My tuppence worth.? TEF?
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It seems their BOM totals $190USD.? You can buy a basic kit w/ acrylic front/rear panels and mike, shipped via DHL, for $160USD.? I guess there is a price for education!
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Re: QUESTION - is it possible to get a TX output of CW in A1A?
Loris,
I do not claim to be an expert on mixers.? I am only an amateur at understanding how they work.? Here is what I think would happen.
The DC voltage would be a 0Hz signal that is being added to the BFO frequency which would put the BFO signal on the input to the SSB filter.? So yes to your question.? Biasing the product detector would pass the BFO signal to the SSB filter.? In the ?BITX v6 That would send an 11.056Hz signal to a filter that is designed to pass signals from 11.057MHz to 11.059MHz so there would be a much-reduced signal being sent to the following stages for frequency mixing and amplification.? In a properly adjusted rig that could be as much as 30db to 40db down.
Note that the above BFO and Filter frequencies are approximate for description only.? They would vary depending on the specifics set for the rig under test and the actual SSB filter characteristics.
If the intent is to use it for CW like is done in the first mixer of the ?BITX, then as is done there you would need to adjust the BFO frequency on key down so that it will generate the correct signal to get through the SSB filter, then further adjust one of the later mixers to be on the correct frequency to transmit.
Again, these are my thoughts.? I am open to any comments or corrections.
73
Evan
AC9TU
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Vishay bought International Rectifier. The Vishay parts are the direct lineal descendents of the original IRF parts.
Technology has improved a lot since the introduction of IRF510 devices in the early 1980s.? Raw material grading, dhigh resolution handling and laser trimming has
become standard.? IRF has apparently licensed manufacturing of IRF devices to
Samsung and Vishay, and probably several others.? This would seem to indicate
that other manufacturer's clones of the original IRF device may be improved
models.? It would take some highly technical testing to determine if a particular
IRF510 device is as good as the original IRF device, or if it exceeds the quality
of its original design.
Large marketing organizations like Digikey or Mouser do not have testing facilities
for determining as-manufactured quality of one source over another.? We have
to trust that they have chosen the best quality and least-cost manufacturers.
Some on-line sales outlets are focused on buying and selling of end-of-run surplus components.? If these items are surplus for space industry or similar
high reliability projects they could be best-in-the-industry.? Or, if they are
surplus from the toy industry they could be worst-of-breed components.?
For the IRF510 devices it might be possible to build a decent test jig with
square-wave input, very high frequency scope monitoring, and calibration
to verify test results.? This is probably way beyond the capability of most
of us, and could be expensive to build.? Thoughts in this area are along the
line of using a calibrated and tuned detector at various harmonic frequency
points to see how much of the input harmonic energy is being output, and
at what level.? It gets complicated very quickly.
Arv _._
On Tue, Apr 13, 2021 at 10:49 AM Timothy Fidler < engstr@...> wrote: It is worth noting that Hans SUmmers of Qrp Labs will use the Vishay IRF510s and none other. He did a lot of tests before he came to that conclusion.
If you go to him for spare parts for a Qrp Labs kit - that is what he will sell you.? I don't believe he offers them as a? general on line sale part because of his restock costs.?
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Jonathan Kayne, KM4CFT did post about the project here a couple of times - /g/BITX20/topic/only_noise_when_connected_to/71596559?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,71596559
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QUESTION - is it possible to get a TX output of CW in A1A?
I ask to the most experienceds of me in the use of MIXERS:
if I inject a direct voltage (eg 1Vdc) to the BF input of the modulation mixer, is it possible that the BFO frequency comes out unmodulated?
What will be the attenuation of the output frequency?
Thanks for the replies.
73 de IW4AJR Loris
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I found that link from the "COCORICO French Touch" link today.
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
A search for IRF510 on the digikey website finds 11 hits.
Anything that is not Vishay is "obsolete".
Half are in a D2PAK case.
Here's the one you want, from Vishay in a TO220 case, they have 359 in stock:
? ??
Item?78-IRF510PBF-BE3 on Mouser is that same VIshay part, slightly cheaper, they have 4040 in stock.
? ?
Mouser also has a bunch of other IRF510's, half of them obsolete, many of them in the D2PAK case.
Jameco says the manufacturer of their IRF510 is "Major Brands", which I assume means
they buy from a number of sources, you get pot luck.? I doubt we've heard the name of whoever manufactures them.
MPJA makes no claim about who makes theirs, so again they likely switch around:
Jerry, KE7ER
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On Tue, Apr 13, 2021 at 07:25 PM, john wrote:
Just tried the link and got a 404 result, so went to digikey, looked the irf510 up and got a status page saying "0" in stock, and "obsolete" from them.
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Just tried the link and got a 404 result, so went to digikey, looked the irf510 up and got a status page saying "0" in stock, and "obsolete" from them.
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Digikey has the Vishay IRF510 for less than a dollar.
?
<
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I met WA2EBY at a Hamfest years ago. I asked him what modeling software did he use when designing the amplifier, He replied "An X-ACTO knife and a piece of copper clad PCB."
?
Mike N2MS
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On 04/13/2021 3:05 PM Jerry Gaffke via groups.io <jgaffke@...> wrote:
?
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The WA2EBY amp is the first successful broadband HF linear amp
using the IRF510's that I'm aware of.
Once that was working well with IR devices, there was some debate
why Vishay devices did not work so well.
Eventually, with a minor circuit change somebody figured out how to make both devices work fine.
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An interesting link I discover today :?
73 - Pierre - FK8IH
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Re: Talk: An Evening with Bob Heil K9EID Tuesday 13th April 8 pm BST (which is 1900 UTC)
This was very good. I had heard most of the talk before but the pictures really made it more understandable.
Sam
WY8V
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On Apr 13, 2021, at 6:04 PM, Vince Vielhaber <vev@...> wrote:
Says it was streamed live 4 hours ago, which is about right.
Vince - K8ZW.
On 04/13/2021 06:52 PM, Dallas wrote:
I listened to this while playing golf
today and what I heard was excellent. I would like to re-listen now while
at home. The YouTube link doesn¡¯t show it
was recorded. Is there a recording I can watch now?
thanks
Dallas, N5fee --
K8ZW
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Re: Talk: An Evening with Bob Heil K9EID Tuesday 13th April 8 pm BST (which is 1900 UTC)
Says it was streamed live 4 hours ago, which is about right.
Vince - K8ZW.
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On 04/13/2021 06:52 PM, Dallas wrote: I listened to this while playing golf
today and what I heard was excellent. I would like to re-listen now while
at home. The YouTube link doesn¡¯t show it
was recorded. Is there a recording I can watch now?
thanks
Dallas, N5fee
--
K8ZW
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Re: Talk: An Evening with Bob Heil K9EID Tuesday 13th April 8 pm BST (which is 1900 UTC)
I listened to this while playing golf
today and what I heard was excellent. I would like to re-listen now while
at home. The YouTube link doesn¡¯t show it
was recorded. Is there a recording I can watch now?
thanks
Dallas, N5fee?
|
Shirley Dulcey KE1L
Loris Bollina
john rader